ref: f43df64325efb80fc48a85009df016477238b21b
dir: /sys/src/cmd/html2ms.c/
#include <u.h>
#include <libc.h>
#include <ctype.h>
#include <bio.h>
typedef struct Tag Tag;
typedef struct Attr Attr;
typedef struct Text Text;
struct Attr {
char attr[64];
char val[256-64];
};
struct Tag {
Tag *up;
char tag[32];
Attr attr[16];
int nattr;
int opening;
int closing;
void (*close)(Text *, Tag *);
union {
void *aux;
};
};
struct Text {
char* fontstyle;
char* fontsize;
int pre;
int pos;
int space;
int output;
int aftertag;
char *bp;
char *wp;
int nb;
};
void eatwhite(void);
void parsetext(Text *, Tag *);
int parsetag(Tag *);
int parseattr(Attr *);
void flushtext(Text *);
char* getattr(Tag *, char *);
int gotattr(Tag *, char *, char *);
int gotstyle(Tag *, char *, char *);
void reparent(Text *, Tag *, Tag *);
void debugtag(Tag *, char *);
Biobuf in;
void
emitbuf(Text *text, char *buf, int nbuf)
{
int nw;
nw = text->wp - text->bp;
if((text->nb - nw) < nbuf){
if(nbuf < 4096)
text->nb = nw + 4096;
else
text->nb = nw + nbuf;
text->bp = realloc(text->bp, text->nb);
text->wp = text->bp + nw;
}
memmove(text->wp, buf, nbuf);
text->wp += nbuf;
}
void
emitrune(Text *text, Rune r)
{
char buf[UTFmax+1];
if(r == '\r' || r =='\n'){
text->pos = 0;
text->space = 0;
}else
text->pos++;
emitbuf(text, buf, runetochar(buf, &r));
}
void
emit(Text *text, char *fmt, ...)
{
Rune buf[64];
va_list a;
int i;
if(fmt[0] == '.' && text->pos)
emitrune(text, '\n');
va_start(a, fmt);
runevsnprint(buf, nelem(buf), fmt, a);
va_end(a);
for(i=0; buf[i]; i++)
emitrune(text, buf[i]);
}
void
restoreoutput(Text *text, Tag *)
{
text->output = 1;
}
void
ongarbage(Text *text, Tag *tag)
{
if(text->output == 0)
return;
tag->close = restoreoutput;
text->output = 0;
}
void
onmeta(Text *, Tag *tag)
{
tag->closing = 1;
}
void
onp(Text *text, Tag *)
{
emit(text, ".LP\n");
}
void
restorepre(Text *text, Tag *)
{
text->pre = 0;
emit(text, ".DE\n");
}
void
onpre(Text *text, Tag *tag)
{
if(text->pre)
return;
tag->close = restorepre;
text->pre = 1;
emit(text, ".DS L\n");
}
void
onli(Text *text, Tag *tag)
{
if(tag->up && cistrcmp(tag->up->tag, "ol") == 0)
emit(text, ".IP\n");
else
emit(text, ".IP \\(bu\n");
if(tag->up)
tag->up->close = onp;
}
void
onh(Text *text, Tag *tag)
{
emit(text, ".SH\n");
tag->close = onp;
}
void
onbr(Text *text, Tag *tag)
{
tag->closing = 1;
emit(text, ".br\n");
if(cistrcmp(tag->tag, "hr") == 0)
emit(text, "\\l'5i'\n.br\n");
}
void
fontstyle(Text *text, char *style)
{
if(strcmp(text->fontstyle, style) == 0)
return;
text->fontstyle = style;
emit(text, "\\f%s", style);
}
void
fontsize(Text *text, char *size)
{
if(strcmp(text->fontsize, size) == 0)
return;
text->fontsize = size;
emit(text, ".%s\n", size);
}
void
restorefontstyle(Text *text, Tag *tag)
{
fontstyle(text, tag->aux);
}
void
restorefontsize(Text *text, Tag *tag)
{
fontsize(text, tag->aux);
}
void
oni(Text *text, Tag *tag)
{
tag->aux = text->fontstyle;
tag->close = restorefontstyle;
fontstyle(text, "I");
}
void
onb(Text *text, Tag *tag)
{
tag->aux = text->fontstyle;
tag->close = restorefontstyle;
fontstyle(text, "B");
}
void
ontt(Text *text, Tag *tag)
{
tag->aux = text->fontstyle;
tag->close = restorefontstyle;
fontstyle(text, "C");
}
void
onsmall(Text *text, Tag *tag)
{
tag->aux = text->fontsize;
tag->close = restorefontsize;
fontsize(text, "SM");
}
void
onbig(Text *text, Tag *tag)
{
tag->aux = text->fontsize;
tag->close = restorefontsize;
fontsize(text, "LG");
}
void
endquote(Text *text, Tag *tag)
{
if(cistrcmp(tag->tag, "q") == 0)
emitrune(text, '"');
emit(text, ".QE\n");
}
void
onquote(Text *text, Tag *tag)
{
tag->close = endquote;
if(cistrcmp(tag->tag, "q") == 0)
emit(text, ".QS\n\"");
else
emit(text, ".QP\n");
}
typedef struct Table Table;
struct Table
{
char *fmt;
char *bp;
int nb;
Table *next;
Table *prev;
int enclose;
int brk;
Text save;
};
Tag*
tabletag(Tag *tag)
{
if(tag == nil)
return nil;
if(cistrcmp(tag->tag, "table") == 0)
return tag;
return tabletag(tag->up);
}
void
dumprows(Text *text, Table *s, Table *e)
{
for(; s != e; s = s->next){
if(s->enclose)
emit(text, "T{\n");
if(s->nb <= 0)
emit(text, "\\ ");
else
emitbuf(text, s->bp, s->nb);
if(s->enclose)
emit(text, "\nT}");
emitrune(text, s->brk ? '\n' : '\t');
}
}
void
endtable(Text *text, Tag *tag)
{
int i, cols, rows;
Table *t, *h, *s;
Tag *tt;
/* reverse list */
h = nil;
t = tag->aux;
for(; t; t = t->prev){
t->next = h;
h = t;
}
/*
* nested table case, add our cells to the next table up.
* this is the best we can do, tbl doesnt support nesting
*/
if(tt = tabletag(tag->up)){
while(t = h){
h = h->next;
t->next = nil;
t->prev = tt->aux;
tt->aux = t;
}
return;
}
cols = 0;
rows = 0;
for(i = 0, t = h; t; t = t->next){
i++;
if(t->brk){
rows++;
if(i > cols)
cols = i;
i = 0;
}
}
i = 0;
for(t = h; t; t = t->next){
i++;
if(t->brk){
while(i < cols){
s = mallocz(sizeof(Table), 1);
s->fmt = "L";
s->brk = t->brk;
t->brk = 0;
s->next = t->next;
t->next = s;
i++;
}
break;
}
}
s = h;
while(s){
emit(text, ".TS\n");
if(gotattr(tag, "align", "center"))
emit(text, "center ;\n");
i = 0;
for(t = s; t; t = t->next){
emit(text, "%s", t->fmt);
if(t->brk){
emitrune(text, '\n');
if(++i > 30){
t = t->next;
break;
}
}else
emitrune(text, ' ');
}
emit(text, ".\n");
dumprows(text, s, t);
emit(text, ".TE\n");
s = t;
}
while(t = h){
h = t->next;
free(t->bp);
free(t);
}
}
void
ontable(Text *, Tag *tag)
{
tag->aux = nil;
tag->close = endtable;
}
void
endcell(Text *text, Tag *tag)
{
Table *t;
Tag *tt;
int i;
if((tt = tabletag(tag)) == nil)
return;
if(cistrcmp(tag->tag, "tr") == 0){
if(t = tt->aux)
t->brk = 1;
} else {
t = tag->aux;
t->bp = text->bp;
t->nb = text->wp - text->bp;
for(i=0; i<t->nb; i++)
if(strchr(" \t\r\n", t->bp[i]) == nil)
break;
if(i > 0){
memmove(t->bp, t->bp+i, t->nb - i);
t->nb -= i;
}
while(t->nb > 0 && strchr(" \t\r\n", t->bp[t->nb-1]))
t->nb--;
if(t->nb < 32){
for(i=0; i<t->nb; i++)
if(strchr("\t\r\n", t->bp[i]))
break;
t->enclose = i < t->nb;
} else {
t->enclose = 1;
}
if(gotstyle(tag, "text-align", "center") || gotstyle(tt, "text-align", "center"))
t->fmt = "c";
else
t->fmt = "L";
t->prev = tt->aux;
tt->aux = t;
*text = t->save;
}
}
void
oncell(Text *text, Tag *tag)
{
Tag *tt;
if((tt = tabletag(tag)) == nil)
return;
if(cistrcmp(tag->tag, "tr")){
Table *t;
tt = tag->up;
while(tt && cistrcmp(tt->tag, "tr"))
tt = tt->up;
if(tt == nil)
return;
reparent(text, tag, tt);
t = mallocz(sizeof(*t), 1);
t->save = *text;
tag->aux = t;
text->bp = nil;
text->wp = nil;
text->nb = 0;
text->pos = 0;
text->space = 0;
} else
reparent(text, tag, tt);
tag->close = endcell;
}
struct {
char *tag;
void (*open)(Text *, Tag *);
} ontag[] = {
"b", onb,
"big", onbig,
"blockquote", onquote,
"br", onbr,
"cite", oni,
"code", ontt,
"dfn", oni,
"em", oni,
"h1", onh,
"h2", onh,
"h3", onh,
"h4", onh,
"h5", onh,
"h6", onh,
"head", ongarbage,
"hr", onbr,
"i", oni,
"img", onmeta,
"kbd", ontt,
"li", onli,
"link", onmeta,
"meta", onmeta,
"p", onp,
"pre", onpre,
"q", onquote,
"samp", ontt,
"script", ongarbage,
"small", onsmall,
"strong", onb,
"style", ongarbage,
"table", ontable,
"td", oncell,
"th", oncell,
"tr", oncell,
"tt", ontt,
"var", oni,
};
void
eatwhite(void)
{
int c;
while((c = Bgetc(&in)) > 0){
if(strchr("\n\r\t ", c) == nil){
Bungetc(&in);
return;
}
}
}
void
parsecomment(void)
{
char buf[64];
int n, c;
n = 0;
eatwhite();
while((c = Bgetc(&in)) > 0){
if(c == '>')
return;
if(n == 0 && c == '-'){
while((c = Bgetc(&in)) > 0){
if(c == '-')
if(Bgetc(&in) == '-')
if(Bgetc(&in) == '>')
return;
}
}
if(n+1 < sizeof(buf)){
buf[n++] = c;
if(n != 7 || cistrncmp(buf, "[CDATA[", 7))
continue;
while((c = Bgetc(&in)) > 0){
if(c == ']'){
if(Bgetc(&in) == ']'){
if(Bgetc(&in) != '>')
Bungetc(&in);
return;
}
}
}
}
}
}
int
parseattr(Attr *a)
{
int q, c, n;
n = 0;
eatwhite();
while((c = Bgetc(&in)) > 0){
if(strchr("</>=?!", c)){
Bungetc(&in);
break;
}
if(strchr("\n\r\t ", c))
break;
if(n < sizeof(a->attr)-1)
a->attr[n++] = c;
}
if(n == 0)
return 0;
a->attr[n] = 0;
n = 0;
eatwhite();
if(Bgetc(&in) == '='){
eatwhite();
c = Bgetc(&in);
if(strchr("'\"", c)){
q = c;
while((c = Bgetc(&in)) > 0){
if(c == q)
break;
if(n < sizeof(a->val)-1)
a->val[n++] = c;
}
} else {
Bungetc(&in);
while((c = Bgetc(&in)) > 0){
if(strchr("\n\r\t </>?!", c)){
Bungetc(&in);
break;
}
if(n < sizeof(a->val)-1)
a->val[n++] = c;
}
}
} else
Bungetc(&in);
a->val[n] = 0;
return 1;
}
int
parsetag(Tag *t)
{
int n, c;
t->nattr = 0;
t->opening = 1;
t->closing = 0;
n = 0;
eatwhite();
while((c = Bgetc(&in)) > 0){
if(c == '>')
break;
if(strchr("\n\r\t ", c)){
if(parseattr(t->attr + t->nattr))
if(t->nattr < nelem(t->attr)-1)
t->nattr++;
continue;
}
if(n == 0 && strchr("?!", c)){
parsecomment();
return 0;
}
if(c == '/'){
if(n == 0){
t->opening = 0;
t->closing = 1;
} else
t->closing = 1;
continue;
}
if(n < sizeof(t->tag)-1)
t->tag[n++] = c;
}
t->tag[n] = 0;
return n > 0;
}
Rune
parserune(int c)
{
char buf[10];
int n;
Rune r;
n = 0;
if(c == '&'){
while((c = Bgetc(&in)) > 0){
if(strchr(";&</>\n\r\t ", c)){
if(c != ';')
Bungetc(&in);
if(n == 0)
return '&';
break;
}
if(n == sizeof(buf)-1)
break;
buf[n++] = c;
}
buf[n] = 0;
if(strcmp(buf, "lt") == 0)
return '<';
if(strcmp(buf, "gt") == 0)
return '>';
if(strcmp(buf, "quot") == 0)
return '"';
if(strcmp(buf, "apos") == 0)
return '\'';
if(strcmp(buf, "amp") == 0)
return '&';
/* use tcs -f html to handle the rest. */
} else {
do {
buf[n++] = c;
if(fullrune(buf, n)){
chartorune(&r, buf);
return r;
}
if(n >= UTFmax)
break;
} while((c = Bgetc(&in)) > 0);
}
return 0xFFFD;
}
Rune
substrune(Rune r)
{
switch(r){
case 0x2019:
case 0x2018:
return '\'';
case 0x201c:
case 0x201d:
return '"';
default:
return r;
}
}
void
debugtag(Tag *tag, char *dbg)
{
if(1){
USED(tag);
USED(dbg);
return;
}
if(tag == nil)
return;
debugtag(tag->up, nil);
fprint(2, "%s %s%s", tag->tag, dbg ? dbg : " > ", dbg ? "\n" : "");
}
char*
getattr(Tag *tag, char *attr)
{
int i;
for(i=0; i<tag->nattr; i++)
if(cistrcmp(tag->attr[i].attr, attr) == 0)
return tag->attr[i].val;
return nil;
}
int
gotattr(Tag *tag, char *attr, char *val)
{
char *v;
if((v = getattr(tag, attr)) == nil)
return 0;
return cistrstr(v, val) != 0;
}
int
gotstyle(Tag *tag, char *style, char *val)
{
char *v;
if((v = getattr(tag, "style")) == nil)
return 0;
if((v = cistrstr(v, style)) == nil)
return 0;
v += strlen(style);
while(*v && *v != ':')
v++;
if(*v != ':')
return 0;
v++;
while(*v && strchr("\t ", *v))
v++;
if(cistrncmp(v, val, strlen(val)))
return 0;
return 1;
}
void
reparent(Text *text, Tag *tag, Tag *up)
{
Tag *old;
old = tag->up;
while(old != up){
debugtag(old, "reparent");
if(old->close){
old->close(text, old);
old->close = nil;
}
old = old->up;
}
tag->up = up;
}
void
parsetext(Text *text, Tag *tag)
{
int hidden, c;
Tag t, *up;
Rune r;
if(tag){
up = tag->up;
debugtag(tag, "open");
for(c = 0; c < nelem(ontag); c++){
if(cistrcmp(tag->tag, ontag[c].tag) == 0){
ontag[c].open(text, tag);
break;
}
}
hidden = getattr(tag, "hidden") || gotstyle(tag, "display", "none");
} else {
up = nil;
hidden = 0;
}
if(tag == nil || tag->closing == 0){
while((c = Bgetc(&in)) > 0){
if(c == '<'){
memset(&t, 0, sizeof(t));
if(parsetag(&t)){
text->aftertag = 1;
if(t.opening){
t.up = tag;
parsetext(text, &t);
if(t.up != tag){
debugtag(tag, "skip");
up = t.up;
break;
}
debugtag(tag, "back");
} else if(t.closing){
up = tag;
while(up && cistrcmp(up->tag, t.tag))
up = up->up;
if(up){
up = up->up;
break;
}
}
}
continue;
}
if(hidden || !text->output)
continue;
r = substrune(parserune(c));
switch(r){
case '\n':
case '\r':
if(text->pre == 0 && text->aftertag)
break;
case ' ':
case '\t':
if(text->pre == 0){
text->space = 1;
break;
}
default:
if(text->space){
if(text->pos >= 70)
emitrune(text, '\n');
else if(text->pos > 0)
emitrune(text, ' ');
}
if((text->pos == 0 && r == '.') || r == '\\')
emit(text, "\\&");
if(r == '\\' || r == 0xA0)
emitrune(text, '\\');
if(r == 0xA0)
r = ' ';
emitrune(text, r);
text->aftertag = 0;
text->space = 0;
}
}
}
if(tag){
debugtag(tag, "close");
if(tag->close){
tag->close(text, tag);
tag->close = nil;
}
if(up)
tag->up = up;
}
}
void
inittext(Text *text)
{
memset(text, 0, sizeof(Text));
text->fontstyle = "R";
text->fontsize = "NL";
text->output = 1;
}
void
main(void)
{
Text text;
Binit(&in, 0, OREAD);
inittext(&text);
parsetext(&text, nil);
emit(&text, "\n");
write(1, text.bp, text.wp - text.bp);
}